Esm 266 passive microwave remote sensing
Download
1 / 28

ESM 266: Passive microwave remote sensing - PowerPoint PPT Presentation


  • 322 Views
  • Updated On :

ESM 266: Passive microwave remote sensing. Jeff Dozier. Frequency-wavelength relation. Generally in the microwave part of the spectrum we use frequency instead of wavelength Typically measured in s –1 , called Hertz (Hz) Most often Gigahertz (GHz) = 10 9 Hz. Microwave band codes.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'ESM 266: Passive microwave remote sensing' - KeelyKia


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

Frequency wavelength relation l.jpg
Frequency-wavelength relation

  • Generally in the microwave part of the spectrum we use frequency instead of wavelength

  • Typically measured in s–1, called Hertz (Hz)

    • Most often Gigahertz (GHz) = 109Hz



Advantages of passive microwave remote sensing l.jpg
Advantages of passive microwave remote sensing

  • Sees through clouds at lower frequencies

  • Long heritage, various instruments since 1978

  • Emissivity sensitive to state of surface, particularly moisture

    • Soil moisture

    • Snow-water equivalent

    • (water is ~80× as absorptive as ice at these frequencies, whereas in visible through infrared, water and ice have similar absorption coefficients)

  • But, because of small amount of energy emitted, pixel size must be large




Planck equation f frequency temperature l.jpg
Planck equation = f(frequency,Temperature)

Planck radiation at20,000 GHz is 36,000greater than at 37 GHz,so pixels at lower frequenciesmust be bigger


Rayleigh jeans approximation to planck equation l.jpg
Rayleigh-Jeans approximation to Planck equation

  • Linear relation between Planck radiation and frequency, on a log-log plot, suggests a power function

http://en.wikipedia.org/wiki/Taylor_series


The really useful simplification involves emissivity and brightness temperature l.jpg
The really useful simplification involves emissivity and brightness temperature

  • Emissivity varies with frequency and polarization


Eos aqua satellite afternoon overpass l.jpg
EOS brightness temperatureAqua satellite (afternoon overpass)

  • Six instruments, 3 in microwave

  • AIRS

  • CERES

  • AMSR-E, Advanced Microwave Scanning Radiometer for EOS

    • AMSR also flies on ADEOS-II (Japanese)

  • AMSU, Advanced Microwave Sounding Unit

  • HSB, Humidity Sounder for Brazil

  • MODIS


Sea ice from amsr sea of okhotsk l.jpg
Sea ice from brightness temperatureAMSR, Sea of Okhotsk

Sea ice, 18 Jan 2003

Motion vectors, 10hrs


Amsr e products l.jpg
AMSR-E products brightness temperature

  • 6 frequencies, 12 channels (dual polarization), from 6.9-89 GHz

    • Precipitation rate

    • Cloud water

    • Water vapor

    • Sea-surface winds

    • Sea-surface temperature

    • Sea ice

    • Snow-water equivalent

    • Soil moisture


Aqua prior to launch l.jpg

Earth-viewing side brightness temperature

Aqua Prior to Launch

Space-viewing side


Aqua s delta ii rocket l.jpg
Aqua’s Delta II Rocket brightness temperature

(photos by Bill Ingalls)


The aqua sounding suite l.jpg
The Aqua Sounding Suite brightness temperature

Humidity Sounder for Brazil (HSB)

Atmospheric Infrared Sounder (AIRS)

Advanced Microwave Sounding Unit (AMSU; two units)

AMSU A1

AMSU A2


Key improvements anticipated from airs amsu hsb data l.jpg
Key Improvements Anticipated from AIRS/AMSU/HSB Data brightness temperature

  • Atmospheric temperatures to accuracies of 1 K in 1-km layers.

  • Atmospheric humidities to 10 % in 2-km layers.

  • Resultant improved weather forecasting.

Launch of a radiosonde


Sample airs infrared spectra l.jpg
Sample AIRS Infrared Spectra brightness temperature

a. Data from all 2378 AIRS infrared channels for one footprint off the west coast of South Africa, June 13, 2002, 1:30 UTC.

500 1000 1500 2000 2500 wavenumber (cm-1)

20 10 6.7 5 4 wavelength (m)

b. Detail showing the leftmost 128 of the 2378 channels in plot a.


Texas thunderstorms as seen in amsu and hsb imagery june 16 2002 l.jpg
Texas Thunderstorms as Seen in brightness temperatureAMSU and HSB Imagery, June 16, 2002

AMSU Ch. 2 (31.4 GHz)

AMSU Ch. 3 (50.3 GHz)

AMSU Ch. 4 (52.8 GHz)

AMSU Ch. 5 (53.94 GHz)

HSB Ch. 2 (150 GHz)

HSB Ch. 3 (183±1 GHz)

HSB Ch. 4 (183±3 GHz)

HSB Ch. 5 (183±7 GHz)


Rain rate images from amsu hsb june 16 2002 l.jpg
Rain Rate Images from AMSU/HSB brightness temperature June 16, 2002

Scandinavia

South central U.S.


Hurricane alma west of mexico may 29 2002 from hsb and airs l.jpg
Hurricane Alma, west of Mexico, brightness temperatureMay 29, 2002, from HSB and AIRS

HSB 150 GHz data

AIRS Visible/Near IR data

(images courtesy of the AIRS Science Team)


Surface conditions and moisture streams in the vicinity of northern europe july 20 2002 l.jpg
Surface Conditions and Moisture Streams brightness temperaturein the Vicinity of Northern Europe, July 20, 2002

Surface Conditions from AMSU

Moisture Streams from HSB



Global sea surface temperatures from amsr e june 2 4 2002 l.jpg
Global Sea Surface Temperatures brightness temperaturefrom AMSR-E, June 2-4, 2002

(image courtesy of NASDA)


Typhoon in the east china sea july 4 2002 from amsr e l.jpg
Typhoon in the East China Sea brightness temperatureJuly 4, 2002, from AMSR-E

Japan

China

AMSR-E image, 2:26 a.m. Japan Standard Time (JST).

Taiwan

Philippines


Slide25 l.jpg
Precipitation over the Eastern U.S. and Vicinity, from AMSR-E and the TRMM Microwave Imager (TMI), June 5, 2002

TMI Total Rainfall

AMSR-E Total Rainfall

(images courtesy of Chris Kummerow and Bob Adler)



Sample record to be extended with the amsr e data north polar sea ice extents l.jpg
Sample Record to be Extended with the 2002 (bottom), from AMSR-EAMSR-E Data: North Polar Sea Ice Extents

Ice extent deviations from the Nimbus 7 SMMR and DMSP SSMI

(extended from Parkinson et al., 1999)


Amsr products and algorithms l.jpg
AMSR products and algorithms 2002 (bottom), from AMSR-E

  • AMSR Algorithm Theoretical Basis Documents

  • Land surface parameters

    • Soil moisture, surface temperature, vegetation water

  • Brightness temperatures

  • Ocean

    • Sea-surface temperature, wind speed, water vapor, cloud water

  • Rainfall (works best over oceans)

  • Sea ice

    • Concentration, temperature, snow on sea ice

    • Nice graphic from New York Times on sea ice decline

  • Snow water equivalent

    • For dry snow, snow reduces apparent brightness temperature from soil

    • For wet snow, mainly detects that snow is wet


ad